This invention relates to telecommunication, and more particularly to a telephone system ring generator.
In conventional local loop systems, a central office communicates with wire-line subscribers (e.g., telephones) through subscriber loop interface circuits located in the central office. Generally, a ring generator located at the central office rings subscribers. The ring generator applies an alternating voltage of approximately 40-80 volts across subscribers (e.g., telephones).
In the emerging wireless telephone industry, local loop telephone systems face a new of set of requirements. In wireless local loop systems, a base station communicates with a central office through wireless communications. Further, the base station may communicate with both wireless and wire-line subscribers. The base station communications with wire-line subscribers through a corresponding subscriber loop interface circuits located at the base station for each wire-line subscriber. In such systems, having a conventional ring generator is not economically feasible. Further, using a conventional ring generator for a wireless local loop system increases the size and cost of the system and decreases system efficiency.
Prior art solutions have included methods of ringing subscribers through subscriber loop interface circuits. However, conventional subscriber loop interface circuits however are made of integrated semiconductor circuits and are voltage limited. As a result, the prior art solutions do not provide acceptable ring voltage amplitudes, loop length, and power efficiency. Further, a subscriber loop interface circuit having a ring generator on-board may not be able to perform both interface functions and generate a ring voltage.
Accordingly, it is an object of the present invention to overcome the problems of the prior art.
It is another object of the present invention to provide a novel subscriber loop interface circuit having a ring generator.
It is yet another object of the present invention to provide a novel ring generator for wireless local loop systems in which a ring voltage is generated through a subscriber loop interface circuit using semiconductor circuity integrated with the subscriber loop interface circuit.
It is still another object of the present invention to provide a novel wireless local loop system wherein a dedicated circuit for ring voltage generation is integrated with a subscriber loop interface circuit in a voltage limited device.
It is a further object of the present invention to provide a novel method for ringing a subscriber through a subscriber loop interface circuit.
It is yet a further object of the present invention to provide a novel subscriber loop interface circuit having an on board ring generator.
It is still yet a further object of the present invention to provide a novel method that dissipates less power than prior art through subscriber loop interface circuit ringing methods.
These and many other objects and advantages of the present invention will be readily apparent to one skilled in the art to which the invention pertains from a perusal of the claims, the appended drawings, and the following detailed description of the preferred embodiments.